
% ============================================
% |        WEIGHT ESTIMATION  TOOL           |
% |											 |
% |               Fuel System                |
% |			                	    		 |
% ============================================

function [W_fs] = WET_Torenbeek_FuelSystem(fs, W_f, Nt, N_eng)

Kfsp = 5.87;            % Kfsp = 5.87 lbs/gal for aviation gasoline
                        % Kfsp = 6.55 for lbs/gal for JP-4
     
    switch fs
        case 0 % For airplanes equipped with non-self-sealing bladder tanks
          W_fs = 1.6 * (W_f/Kfsp)^0.727;
        case 1 % For airplanes equipped with integral fuel tanks(wet wing)
          W_fs = 80*(N_eng + Nt - 1) + 15*(Nt)^0.5 * (W_f/Kfsp)^0.333;
    end

end        